In an active matrix display device, an example of which is a liquid crystal display device, image data written in pixels of a display panel to display images is generated by a drive controller and then temporarily stored in source drivers provided in the display panel. Then, drive signals generated by the image data are supplied to the respective pixels (active elements) based on predetermined control signals.
The display devices available these days are larger in size and achieving higher definitions. Along with the ongoing advancement, increasingly faster transmission speeds (transmission clock frequency) are demanded to supply image data. Conventionally, electronic devices generate unwanted radiation such as electromagnetic wave and/or electric wave during their operations, which are typically called electromagnetic interference (EMI). The electromagnetic and electric waves thus generated by electronic devices adversely affect other circuits, therefore, it is crucial to find solutions for the problems caused by EMI. However, EMI countermeasures are more difficult to fulfill in display devices as the transmission clock frequencies are faster. An invention was disclosed as an effective EMI countermeasure in display devices in larger sizes with higher definitions. The invention divides a display panel into a plurality of drive regions without lowering the transmission clock frequency (see the Patent Document 1). According to the invention, the display panel is divided into two regions, and the divided drive regions are respectively provided with different transmission clock frequencies. This technique succeeds in facilitating upsizing, higher definitions, and EMI countermeasures in display devices.
Patent Document 1 Japanese Unexamined Patent Publication No. 2009-115936